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Membranophoridium connectum
Membranophoridium connectum Stover and Hardenbol, 1994
Plate 4, Figures 22a-23c
Description
Proximate cysts with lenticular bodies having offset parasulcal notches. Endophragm thicker than periphragm, irregularly pitted and without antapical lobation. Periphragm confined to peripheral areas and reinforced and/or supported by short, narrow, relatively widely spaced, radial thickenings within the pericoel. Periphragm continuous dorsally, continuous or interrupted medially along the ventral antapical margin and without conspicuous or consistently-formed protrusions. Archeopyle apical; operculum presumably tetraplacoid and contiguous although constituent paraplates are undifferentiated, secate. Paratabulation indicated by the principal archeopyle suture and short accessory sutures or notches which delimit the lateral boundaries of six precingular paraplates. Other indications of paratabulation absent. Size: intermediate; overall width 60 to 69Ám, body width 51 to 58Ám, pericoel 2 to 6Ám wide.
Comparison
Membranophoridium connectum differs from M. aspinatum Gerlach 1971 ex Gocht 1969 by having much narrower marginal extensions of the periphragm and supporting structures within the periphragm and by lacking antapical extremities or well-defined lobations. The new species differs from M. bilobatum Michoux 1985 by the presence of radial thickenings within the periphragm, an irregularly pitted endophragm and the absence or poor development of antapical projections.
Types
Holotype: Plate 4, figures 22a-c. Paratype: Plate 4, figures 23a-b. Both specimens from the Boom Composite Section sample at 45.96 meters (= Cored Reconnaissance Hole sample at a drill depth of 35.80 meters).
Occurrence
Membranophoridium connectum occurs only in the upper part of the Boom Composite Section in the Putte Member of the Boom Formation between 44.20 and 56.90 meters. The species is particularly common in the sample from the 44.50 meter level.
Plate 4, Figures 22a-23c
Description
Proximate cysts with lenticular bodies having offset parasulcal notches. Endophragm thicker than periphragm, irregularly pitted and without antapical lobation. Periphragm confined to peripheral areas and reinforced and/or supported by short, narrow, relatively widely spaced, radial thickenings within the pericoel. Periphragm continuous dorsally, continuous or interrupted medially along the ventral antapical margin and without conspicuous or consistently-formed protrusions. Archeopyle apical; operculum presumably tetraplacoid and contiguous although constituent paraplates are undifferentiated, secate. Paratabulation indicated by the principal archeopyle suture and short accessory sutures or notches which delimit the lateral boundaries of six precingular paraplates. Other indications of paratabulation absent. Size: intermediate; overall width 60 to 69Ám, body width 51 to 58Ám, pericoel 2 to 6Ám wide.
Comparison
Membranophoridium connectum differs from M. aspinatum Gerlach 1971 ex Gocht 1969 by having much narrower marginal extensions of the periphragm and supporting structures within the periphragm and by lacking antapical extremities or well-defined lobations. The new species differs from M. bilobatum Michoux 1985 by the presence of radial thickenings within the periphragm, an irregularly pitted endophragm and the absence or poor development of antapical projections.
Types
Holotype: Plate 4, figures 22a-c. Paratype: Plate 4, figures 23a-b. Both specimens from the Boom Composite Section sample at 45.96 meters (= Cored Reconnaissance Hole sample at a drill depth of 35.80 meters).
Occurrence
Membranophoridium connectum occurs only in the upper part of the Boom Composite Section in the Putte Member of the Boom Formation between 44.20 and 56.90 meters. The species is particularly common in the sample from the 44.50 meter level.